code: def hybrid_forward(self, F, x):
      x = self.psp(x)
      return self.block(x)
  
imports: from mxnet.gluon import nn
  from mxnet.context import cpu
  from mxnet.gluon.nn import HybridBlock
  from .segbase import SegBaseModel
  from .fcn import _FCNHead
label_desc: Use image node_id 2 for calling the _PSPHead obj's underlying member method code with example usage: obj.hybrid_forward(F, x) and returns: self